Kevin Keller
Proof of concept prototyping is, at its core, a quick and dirty mock-up, intended to validate a fundamental idea or overall product architecture (Primary Feature). Sometimes these prototypes are used in an effort to get a sense of scale for a product, other times to validate a mechanism approach or even to test usability. The primary goal of the POC prototype is to get those answers WITHOUT spending too much time and money. The following are a few strategies for prototyping quickly and inexpensively.
Focus on a single feature
When you have a vision for a product, it is tempting to include all the features and see the entire product or assembly (or as many features as possible) in the first pass. However, incorporating a larger number of features can take longer and obscure, or even work against, the critical feature you are focusing on. The challenge is figuring out how to represent the missing features just enough so that your prototype is not missing the context of the final product.
During our development of the Sharper Image Fogless Mirror, we wanted to design an adjustable, magnetic connection to the wall. The key was to determine an effective mounting cup radius and magnet strength to hold the full mirror at any position. We estimated the final product weight, used some off-the-shelf parts and added miscellaneous materials from our shop to get a “Ballpark” size and weight. This prototype gave us the confidence to move forward with this approach.
(Prototype magnet connection on the left and production mirror on the right.)
Different materials to replicate size
3D printing has completely changed how we design and prototype, mostly for the better. However, we often find that engineers always look to 3D printing exclusively for proof of concept prototyping. There are often scenarios where it is not the most effective tool for the job. The most common reason is that the part or assembly is quite large and 3D printing will take too long, cost too much or not have the right properties. While testing out the display lift mechanism for the Lancer IBD BOLD 30i, we cut plywood to mount the linkage, simulate the display and hung weight to provide the same mass properties as the actual display. Plywood is easy to source and with a traditional printer (2D paper), you can print out a nice drill template. Basic shop tools can be used to get the overall shape of the pieces.
(Prototype display with a hanging weight to simulate the weight of the display. Production display on the right.)
Electronics simulation
When prototyping lighting and other functional electronic features, it is important to get a sense of the output (lighting) and usability (layout and interface). A more formal prototype for custom electronics can take weeks because you need to select the components, the electrical designer needs to do a layout, the board needs to be fabricated and firmware may be needed to get the hardware to function. Using off the shelf components and hobby microcontrollers/microprocessors (Arduino / Raspberry PI) allow us to quickly simulate basic electronic functionality such as running motors, powering LED’s, switches, etc. This helps define the usability and architecture and gives a good starting point for components to be used in the first fully functional electronics prototype.
(Using a desktop mill and microcontroller we can layout a basic board and drive LED’s to test a basic lighting feature. Production light on the right.)
The most important thing to remember in Proof of Concept prototyping is that we are looking for quick AND efficient validation. It is really important to be creative in finding ways to isolate what you are testing (Primary Feature). If you can do that then secondary features can be either eliminated or simplified to get you to your answer as quickly as possible. GOOD LUCK!
